Hey guys, My 1.6 mk2 golf (with weber carb) seems very hesistant when putting my foot down. The revs will initially dip then increase. If I pull the choke out little bit, the car works fine. The carb has been approx setup using the weber instructions. I've just had a 8v GTI manifold and downpipe fitted, and a new heater matrix. Not sure if this has anything to do with my problem, but while I was replacing the manifold, my weber carb had been left outside and got wet. I've cleaned it up with carb cleaner and gave the car a good thrashing. The exhaust also seems to be smoking abit, white/clear smoke which smells of petrol (probably due to the carb not being accurately set up). I'm abit worried the head gasket has gone - I did see some mayonaise on the oil filler, but I'm hoping that was because the car hasnt been started in 2 months, and when it has been started it hasnt got to temperature. Someone please help! Thanks.
Best thing to do is to do a compression test and check to see whether there is anything amiss. Then, take the car to get properly set up. On my other car (mini) once it was set up on the rollers it drove lie a dream, it too was a little hesitant like yours but i think it was due to over fueling.
Could be an accelerator pump problem. With engine off, rapidly twist the bit on the carb that the accelerator cable attaches to, to imitate you putting your foot down abruptly, and listen/watch for a good spray of petrol down the primary barrel. If you don't hear/see anything, you've found your fault. What you do about it is another matter; one for maxmo/Nordoff/other Weber expert.
Thanks Steve, I was thinking of getting a compression test done, although I'm not loosing any water or oil. Thank you EZ_Pete, I'll give that a go tomorrow morning - I'm very tempted to go out now, but its freezing. Do you know if water could damage the accelerator pump? ie me leaving the carb outside! Either way I'm buggered, headgasket or carb related. Bare in mind the carb is only afew years old.
Dunno; wouldn't have thought so in a short time-frame. There are a lot of bare machined alloy surfaces inside a carb that can corrode in the presence of water, but I'd've thought that would only have bad effects over weeks/months/years.
Well I tried what EZ Pete suggusted and I could hear (and smell) petrol being sprayed into the carb, so I guess my accelerator pump is ok. Any any ideas? I'm really loosing the will to continue with this car. [:^(] [:^(] [:^(]
If you look through threads that I've started previously you'll see that I have also had a hesitation/stutter/misfire (in fact the car still has it but is sorn at the moment), it would bog down under acceleration unless the throttle was pressed very gently. The carb has been stripped and cleaned and re-gasketed, new jets and emulsion tubes installed (my carb was bought secondhand), accelerator pump jet replaced, tuned by two different beardies - one of whom believed the problem was ignition related and replaced the vacuum advance on the distributor. The new vacuum unit made a slight improvement. I have also replaced rotor arm, dizzy cap, plugs, leads, and the coil. The coil made the biggest improvement. We do have one thing in common though - the same problem has occurred after fitting of a GTI manifold and exhaust to a 1600, I wonder if its related? Also, whilst trying to help Jamie_Pyrite recently I noticed that my distributor has a lot more play in its shaft than his. I plan to return my car to normal 'driver' spec over the next couple of months so I'll see if that makes the problem go away before splashing out on a new dizzy. The above probably doesn't help but may give you some food for thought at least
Thanks for your response maxmo. You are right, it doesnt fill me with much confidence. I only fitted the GTI manifold & downpipe becasue mine had cracked & I couldnt find another 1.6L manifold. I dont really fancy reverting back to normal, its too much effort!! I'm sure there are people out there who have fitted a GTI manifold to a 1.6!
i had the same problem after fitting a gti exhaust (but with a g60 downpipe- don't feel good about it though) to my webered 1600- when the second throttle opens it hesitates and/or vibrates. but a day after i got the gti zaust i cleaned my jets and the secondary idle jet got loose and would fall inside when trying to screw it in- it could well be the reason, cos' on the weber guide they say that the purpose of this jet is to prevent hesitating. i got new jet and holder but didn't fit them yet so i'll keep you posted.
Hmmm, looks like the GTI manifold & exhaust mod on a 1600 doesnt seem to be a mod!!! If anyone has had success, please tell.
Have you fitted a GTi cam as well? If not, it might be that GTi exhaust + standard cam is not a very good match. I don't know enough about valve timing/cylinder filling/exhaust scavenging etc. yet to have much idea myself, but someone else out there surely does... The other thing I'd suggest is that you have a re-visit of your ignition timing arrangements. Didn't you re-time it recently with dizzy vac unit disconnected? Might be worth putting it back to 'stock' and seeing if that improves matters.
Are you sure the weber is set up correctly? I really can't see the manifold being the problem. Are you sure dirt isn't passing into the carb from the swirl pot (fuel reservoir) which bolts onto the cam cover? This is quite common and often undiagnosed as the fuel filter filters the fuel before this. Best thing to do is clean it out with thinners. You could try fitting an in-line filter AFTER the reservoir to see if this helps although be advised the fuel is under pressure here and those filters aren't designed for this. Hesitating can also be an ignition problem, even with a weber your car should be 18 before top dead centre at 2250rpm with the vac advance disconnected (unless you have fitted a GTi cam). It may also be worth checking the state of the wires which go from the dizzy to the coil and then to the ignition amplifier on the left hand side of thr scuttle tray as you look at it, failing this get another ignition amplifier from a scrappy and swap it (any MK2 one will do).
I think 18 BTDC at 950rpm with vac line connected is what ElsaWIN says (see page 5 of 5). (And rubjonny!) It is an EZ engine, yeah?
Hi Pete, I havent fitted a GTI cam, just a GTI manifold & downpipe and 16v GTI exhaust system. Hmmm, maybe GTI exhaust & standard cam isnt a good match, but I'm sure someone out there has tried this. I did redo my ignition timing, all back to stock, dizzy vac connected & I used the bellhouse timing mark (approx 17-19 degrees). This didnt make any difference at all. When I start the car next (hopefully tonight), I'll post a video of the symtoms, that might help someone see my problem.
I've set the carb using the weber manual (which I have done in the past & then got a garage to set accurately). However prevously the when I have set it, the revs didnt drop or the car didnt seem hesistant. It could be the fuel supply, I'll try changing the fuel filter first. I've noticed I didnt mention in my original post, that the carb had been left outside and possible got wet. I've taken the car out for a good thrashing and sprayed loads of carb cleaner in the carb.
it definitly isnt the manifold & zaust causing the problem, did exactly that on my driver and it went better than it ever had! had the std 1.6 cam, 2e2 carb, ign timing etc. Your problem lies elsewhere.
Hmmm, thats good to know. But a bit annoying. Just a thought, would an air leak in the vaccum cause this?
Sorry got mixed up with the digi timing. I would definitely check the fuel reservoir though. The only thing that is worth thinking about following muppet9966 is carb icing, is the flap on the intake definitely working, this weather you should definitely be on the warm air feed from the exhaust heat sheild
